Trench-sheeting device



Aug, 6, 1929. M. FARRAR 1,723,691

TRENCH SHEETING DEVICE Original Filed May 4, 1925 5 Sheets-Sheet 1 Aug. 6, 1929. V FARRAR 1,723,691

TRENCH SHE ETING DEVICE Original Filed May 4, 1923 5 Sheets-Sheet 2 Aug. 6, 1929. FARRAR 1,723,691

TRENCH SHEETING DEVICE Original Filed May 4, 1923 5 Sheets-Sheet 5 Aug. 6, 1929; FARRAR 1,723,691

TRE NCH SHEETING DEVICE Original Filed May 4, 1923 5 Sheets-Sheet 4 5 Sheets-Sheet 5 1929- M. FARRAR THENCE SHEETING DEVICE Original Filed May 4, 1923 iii Patented Aug. 6, 1929.

MONROE FARRAR,

Application filed May 4, 1923, Serial No. 636,530.

This invention relates to machines for excavating r trenching where the channel formed requires walling to prevent caving.

One object of the invention is to prevent caving of the trench wall during and subsequent to the excavating operation and prior to the placing of the walling timbers.

Another object is to facilitate the introducion of the wall timbers and to assist in positioning them against the trench wall.

Another object is to provide mechanism of the class named which shall be of improved construction, and convenient and officient in operation.

The invention is exemplified in the combination and arrangement of parts shown in the accompanying drawings and described. in the following specification, and it is more particularly pointed out in the appended claims.

In the drawings- Fig. 1 is an elevation of a trenching machine having one embodiment of the present invention applied thereto;

Fig. 2 is a vertical section showing a boom of a trenching machine in operation and showing the inner face of the supporting guards at one side of the boom in elevation;

Fig. 3 is a vertical section showing the wall guards and kerf-cutting chain there-- for;

Fig. 4 is a section on line JP-4t of Fig. 5 is a top plan View of the setting mechanism forming a part present invention;

Fig. 6 is a vertical section showing a modifled form of the invention; and

Fig. 7 is a section substantially on line 7-7 of Fig. 6.

Referring more particularly to the drawings, the numeral 10 designates the frame of a trenching machine having an engine 11 and caterpillar traction mechanism 12 driven thereby. A boom 13 is mounted for movement on the frame 10 in a manner well known in the art and is operated by means of a drivechain 14 connected with the engine 11. The boom 13 carries an endless chain 15 having buckets or scoops 16 thereon which excavate the material from the trench being formed in a manner well known in the art.

The chains 15, as shown in Fig. 2, are driven by sprocket wheels 17 secured to a Fig. 2 timber of the OF DETROIT, MICHIGAN. i 5 TRENCH-SHEETING DEVICE.

Renewed December 31, 1928.

shaft 18 and guide pulleys 19 are mounted n spaced position in the boom 13 for guidmg the chains and buckets. At each side of the boom 13 adjacent the lower end thereof and spaced outwardly therefrom is a guard plate 20 for engaging the walls of the trench it is being cut. The outer face of one of these plates is shown in Fig. 1, and the inner face is illustrated in Fig. 3.

Cross-braces 21 extend across the trench from. one of the guard plates 20 to the other and comprise channel bars secured to the boom 13 having extension bars 22 adjustably connected at each end thereof by means of pins 23. Braces 24 are provided for holdmg the bars 21 in rigid connection with the boom 13. Stifi ening channels or angles 25 may be secured to the inner face of the guard plate 20, if desired.

Guide sprockets 26 are mounted in suitable housings 27 at spaced intervals about the periphery of the guard plates 20 and endless chains 28, one for each guard plate 20 travel upon the sprockets 26. The chains 28 are driven by sprockets 29 on a shaft 30 at the forward end of the guard plates, the shaft 30 being connected by driving chains 31 and 82 to the drive shaft 18. A chain tightener 33 may be provided if desired.

The chains 28 are provided at spaced intervals with teeth 34 having oppositely bent cutting portions 35 for forming a kerf of sufficient width to receive the guard plates 20 and the sprocket housings 27. It will be seen that the kerf-cutting chains form a smooth wall at the sides of the trench and that the guard plates 20 prevent caving of the walls during the operation of the excavator buckets 16. The portion of the wall above the guard plate 20 is supported by an extension or supplemental guard plate 36, one at each side of the machine, and an ranged in the plane of the plate 20. The lower edges of the plates 30 are provided with stiffening angles 37 and are secured by offset brackets 38 to the upper edges of the plates 20. The upper edges of the plates 20 are also provided with angle bars 39 and the brackets 38 provide suflicient space between the bars 37 and 39 for the travel of the kerfcutting chains.-

The plates 36 are provided with extensible braces 40 similar to the braces 21 used in connection with the plates 20. Pivotally connected to the inner faces of the guard plates 36 are spaced links 41. These links have their rear ends pivoted between the flanges of vertically disposed channel irons 42, as shown more particularly in Fig. 5. The channel bars 42 have outer and inner plates 43 and 44 connected to the outer faces of their flanges respectively, the outer plates 43 having their front edges offset inwardly and overlapping the inner faces of the rear edges of the plates 36. Trench jacks 45 are interposed between the channels 42 to hold the plates 43 against the trench walls. The rear edges of the plates 44 are provided with eyes 46 for receiving the open hooks 47 of press frames 48, the frames comprising spaced channel bars having rollers 49 journaled therebetween.

The frames 48 are provided with seats 50 for engaging the heads of trench jacks 51 by which the frames are pressed outwardly against the trench timbers. The seats 50 may be wooden blocks which provide suitable bearings from which the heads of the jacks do not readily slip. The rear edges of the plates 44 also carry supporting brackets 52 on which to rest the forward ends of trench stringers 53 while the trench jacks 54 are being placer. in position between the stringers. Each stringer is preferably provided at its forward end with a ledge 55 for engaging a corresponding shoulder 56 on the rear end of the next adjacent stringer.

In operation, the excavating mechanism is driven in the usual manner to remove the dirt from the trench being formed. At the same time the kerf-cutting chains will provide a groove or kerf at the side of the trench for receiving the guard plates, as previously described. The material betw en the kerf thus formed and the channel formed by the excavating buckets will crumble inwardly and be carried upwardly by the rising'buckets. The guard plates and kerfcutting chains may be adjusted laterally to any desired extent so that the width of the trench may be regulated and atthe same time a true side wall is formed against which the trench timbers will smoothly fit. It will be noted that the guard plates protect the side walls of the portion of the trench in which the excavating mechanism is operating so that caving in of the walls upon the excavator boom and buckets is avoided and the walls are kept true until the timbers are in place. Space is provided between the plates 43 and 44 for the insertion of the wall boards 57. These are lowered'into position by workmen on the bank and are placed against the inner face of the plate 43, as shown in Fig. 5. As the plates 43 are drawn forwardly by the forward movement of the excavator the rear edges of the plates 43 will be drawn from behind the wall timbers and at the same time the rollers 49 will engage the inner faces of the timbers and press them firmly against the wall so that at no time is the material of the trench wall given an opportunity to cave in from the time the trench cut until the trench boards are in place.

While the boards are being held. by the rollers 49 the trench stringers 53 are placed in position with their rear ends supported by the front ends of the stringers already in place and with their front ends resting on the brackets The trench jacks 51 are then inserted between the stringers so that before the frames 48 are withdrawn from contact with the timbers, the stringers 531 will be held in position by the jacks 51. The parallel links 41 permit of vertical movement of the excavator boom independently of the plates 43 and 44 so that the setting of tie timbers is not interfered with by any vertical movement of the excavator boo-m.

t will be seen from Fig. 3 that the apparatus readily accommodates itself to any variation in the depth of the trench. While the boom 13 may move vertically relative to the plates 43 and 44 an upward movement of the boom over an obstruction, as shown in Fig. 3, will exert upward force on the spaced plates so as to raise the plates over the obstruction and the frames 48 being freely pivoted to the plate 44 will follow the gcncral upward trend. The trench stringers may be correspondingly inserted as illustrated in this figure.

In the form of the invention shown in 6 and 7, the guard plates 55 are made continuous and the sprocket wheels 50 on. which the upper runs of the chains 28 travel are spaced inwardly from the inner face of the plates and supported on brackets 57 mounted on the plates. This gives the cutting planes of the kerfcutters a slight angle relative to the plates 55' so that the teeth 34 will project below the lower edge of the plate on the lower run of the chain. but will clear the inner face of the plate on the upper run. The angle is just sntlicicnt. for the teeth to clear where they pass the edge of the plate at the warmest sprmket, which it will be observed from Fig. (3 is about midway between the lines of upper and lower runs.

In this form of the invention the ncccs sity of using walling timbers is entirely obviated by use of follower plates 58, attached one to each plate 55 by links 59 and equalizer 60. Braces 6L are interposed between the follower plates to retain them against the trench walls, the plates being drawn forwardly with the trench machine and being ofsullicient length to permit laying of sewer pipe or other work for which tin ltlt) continuously With trenching machine.

I claim 2-- 1. The combination with the excavating mecl'ianism of a trencl'iing machine, of guard plates extending in the rear of said mechanism for supporting the walls of the trench during the placing of trenching timbers, said plates being secured to said. trenching machine and drawn f rwardly thereby from the rear of the timbers after they have been placed, and followers connected with said trenching machine to engage said timbers and hold them in place during the withdra *al of said guard plates.

2. The combination with the excavating mechanism of a trenching machine, of guard plates extending in the rear of said mechanism for supporting the walls of a trench formed by said mechanism, followers having rollers thereon for engaging timbers positioned against'the inner faces of said guard plates to hold said timbers in place during the withdrawal of said guard plates and means for pressing said followers outwardly against the inner faces of said timbers.

3. The combination With the excavating mechanism of a trenching machine, of guard plates extending in the rear of said mechanism for engaging the walls of the trench formed thereby, and members spaced inwardly from said guard plates to form pockets for receiving walling timbers.

at. In combination with the excavating mechanism of a trenching machine, of guard plates for supporting the walls of a trench formed by said mechanism, and means for retaining waliign timbe 1's adjacent the innor faces of said guard plates din'ing the the advance of the removal of said guard plates from beteen said timbers and the Wall ot the trench.

5. The combination with the excavating mechanism of a trenching machine, of guard plates arranged in the rear of said mechanism for supporting tile side walls of the trench formed thereby, means for retaining walling timbers adjacent the inner faces of said. guard plates, and means for movably ci'mnectmg said ginird plates with said excavating mechanism to permitmovement of said excavating mechanism relative to said guard plates.

6. The combination with the excavating mechanism of a trenching machine, of guard plates arranged at the side of said mechanism and secured thereto, supl'ilemental guard plates disposed in the rear of said first-named guard plates and overlapping the rear edges thereof, and means .ror connecting said supplemental guard, plates to said excavating mechanism to permit relathe trench is intended the Work ro ressin tive vertical movement between said first mentioned guard plates and said mental guard plates.

7. The combination with the excavating mechanism of a trenching machine, of a pair of guard plates connected to said mechanism and disposed in the rear thereof, said guard plates being spaced from one another to provide a pocket for receiving Walling timbers.

8. The combination ith the excavating mechanism of a trenching machine, of guard plates secured to said mechanism at the sides thereof, supplemental guard plates disposed in the rear of said iirst-mentioncd guard plates, link mechanj in con ingr' said supplemental guard. plates with said excavating mechanism to permit vertical reative movement, the adjacent edges of said supplemental guard plates and said first-mentioned guard plates being arranged in OVGll2l1')PlI)g relation, retainer plates adjacent the inner faces of said supplemental plates and spaced therefrom to form pocket for receiving Walling timbers, and followers attached to said retainer plates and having rollers thm'eon for engaging the inner faces of walling timbers disposed in said pockets and for pressing said timbers outwardly against said supplemental plates during the withdrawal of said supplemental plates.

9. The combination with the excavating mechanism of a trenching macl'iine, of guard plates for suprmrting the ails of the tremah formed by said mechanism during the placing of Walling timbers, and means for holding said timbers in position during the placement of props therefor, said holding means being removable after the placement of said props.

10. The combination With the excavating mechanism of a trenching machine, of gun rd plates for supporting the side walls of a trench. formed by said mechanism during the placement of walling timbers, said plates being attached to said mechanism to be drawn forwardly thereby subsequent to the placing of said timbers, and followers con nected with said plates for supporting said timbers against the walls of maid trench to permit placen'ient of props against said timbers, said followers being n'lovablc forwardly with said trenching machine out of engagement with said walling timbers after the props are in place against said timbers.

11. The combination with the excavating mechanism of a trenching machine, of guard plates for supporting the side walls of a trench formed by said machine, means connected with said guard plates for temporarily retaining walling timbers against said side walls, and means mounted on said plates for supporting the forward ends of stringers disposed adjacent the inner faces suppleof the walling timbers while props are being positioned against said stringers.

12. In combination, a trenching machine having a rearwardly and downwardly extending boom, excavating mechanism arranged to travel on said boom, guard plates secured to said boom at the sides thereof for engaging the wall of a trench formed by said excavating mechanism, means for excavating material in front of said guard plates to provide clearance therefor, and means disposed in the rear of said excavating mechanism for supporting the side walls of said trench during the placement of trench timbers.

13. In combination, a trenching machine having a rearwardly and downwardly extending boom, excavating mechanism arranged to travel on said boom, guard plates disposed at the sides of said mechanism for supporting the walls of a trench formed thereby, a cutter for forming clearance space for said guard'plates, supplemental guard plates disposed in the rear of said first-mentioned guard plates and having overlapping edges therewith, said guard plates being movably connected with one another, said supplemental guard plates having clearance space adjacent the innerfaces thereof for placement of walling timbers, follower frames pivotally connected to the rear edges of said supplemental guard plates and having rollers thereon for engaging the inner faces oftimbers placed against said supplemental guard plates, and brackets secured to the rear edges of said supplemental guard plates for supporting props for said timbers during the placement thereof.

14. Means for facilitating the placement of walling timbers, comprising a plate for engaging the face of a wall and having clearance space at the side thereof away from said Wall for receiving a timber, means for drawing said plate in the direction of the plane of said wall to remove said plate from between said wall and said timber, and means for pressing said timber against said wall when said plate is withdrawn.

15. Means for facilitating the placement of walling timbers, comprising a pair of spaced plates having a pocket therebetween for receiving a walling timber, means for drawing said plates along the face of a wall, the rear edge of the plate adjacent the wall being free from obstruction to permit the withdrawal thereof from between the wall and a walling timber, and a presser frame secured to the rear edge of the plate spaced away from said wall and having rollers thereon for engaging a walling timber during the withdrawal of the wall engaging plate.

16. Means for facilitating the placing of walling timbers, comprising a guard plate for engaging the face of a wall, a sustaining plate spaced from said guard plate to provide a pocket for receiving a walling timber, the rear edge of said pocket being open to permit the withdrawal of said plates from a timber placed therebetween, a follower attached to the rear edge of the plate spaced from said wall for engaging said timber as said plates are withdrawn therefrom, means for exert-ing force on said follower to press said timber against said wall, and a bracket mounted on the plate spaced outwardly from said wall for temporarily supporting a propping device whi c it is being placed in position against a timber held by said follower.

17. The combination with excavating mechanism of a trenching machine comprising kerf-cutters and scoops, of shields to support the walls of a trench, said shields being positioned in advance of said scoops for preventing injury of said walls when said scoops are operated.

18. The combination with excavating mechanism of a trenching machine comprising spaced-apart kerf -c11ttcrs for cutting spaced apart narrow cuts and scoops for removing the material between said cuts, of shields for supporting the *alls of said narrow cuts while said scoops are in operation, said shields being positioned in advance of said scoops.

In testimony whereof I have signed my name to this specification on this 2d day of May, A. D. 192-3.

MONROE FARRAR. 

